Lightweighting Identified as Top Fuel Efficiency Driver

Lightweighting is gaining ground in the automotive industry as the preferred method for meeting fuel efficiency standards, although plastics and composites aren't top picks for material substitution.

That's according to the fourth annual survey of automotive insiders from DuPont Co. and WardsAuto.

Forty-nine percent of the participants identified lightweighting as a top focus for improving fuel efficiency, according to the survey, conducted by Penton Market Research and released during the Center for Automotive Research's Management Briefing Seminars in Traverse City.

Nearly half of the survey's 880 respondents work at components or parts manufacturers, a quarter at automakers.

In an unexpected turn, engine efficiency programs came in behind lightweighting, named by only 39% of respondents.

"When we have done this survey in years past, improving engine efficiency and electrification were considered more important, higher priority, were obtaining more effort within the industry players to achieve that goal. But in this year, lightweighting kind of leaped to the top, and we weren't expecting that," Jeff Sternberg, director of automotive technology at DuPont, said in a phone interview.

Others in the industry have picked up on the trend as well. CAR researcher Greg Schroeder discussed the limits of powertrain technologies at the conference Aug. 4.

"I think that what you'll see is that so far the industry's done a fairly decent job in improving the fuel economy of the fleet, but it's going to get a whole lot tougher, and if you look at that, I believe that at the end of the day, it's not just going to be about powertrains," he said. "It's about friction reduction, it's about low rolling resistance tires, and certainly mass reduction is one of the primary solutions for achieving fuel economy."

The increased visibility of lightweighting is in part thanks to high-profile lightweighting projects like the new Ford F-150 and BMW's i3, which both dropped considerable weight by swapping traditional materials for lighter alternatives, Sternberg said. Success with new polymers has also played a role.

"With the advancements that have taken place in incorporating plastics and composites into automotive, into automobiles, to achieve some significant lightweighting, there's just a greater awareness that more can be done than maybe was previously realized," he said. "There's a growing appreciation of the opportunity here."

Among lightweight materials, aluminum is still the preferred material, the survey found.

Last year the family of engineering plastics tied aluminum for the top spot, but in 2014 aluminum slipped ahead again with 27% of votes, compared to engineering plastics' 13%. Eight percent of respondents picked advanced composites as their material of choice, and 16% chose a multi-material solution.

In addition to aluminum's exposure in projects like the F-150, its lead is also due in part to the automotive industry's familiarity with metals, Sternberg said.

"I think that's one of the challenges we have, especially with composites, in the industry, is it's a new type of material. There are all sorts of operations and supply chains, etc., that they aren't as familiar with as they are with metal," he said, mentioning fastening technologies as an example.

"Plastics and composites are relatively new, so I think there's almost an initial reaction: Let's first try to work with the type of material that we know how to deal with, and if and when either that doesn't work or there's a better option, which is often the case with plastics and composites, then maybe they go and they explore those a little further."

Several industry experts at the conference also said they see aluminum remaining the material of choice in automotive lightweighting for years—or decades—to come. So do plastics have a chance?

"I think some of that will come with scale, especially around composites," Sternberg said. "And as larger and larger scales are needed to meet the demand of the growing adoption, I think the auto industry will become much more comfortable with those value chains, with the security of supply and things like that. I think the matter of time is an important consideration."